<title>Large-area single-mode selectively oxidized VCSELs: approaches and experimental</title>

Abstract

We present the investigation of several methods to increase the active diameter of single transverse mode oxide confined VCSELs in both the 850 and 980nm wavelength regimes. Among the concepts considered are mode intensity specific shallow surface etched reliefs, monolithically increased cavity lengths, current confinement matching the fundamental mode intensity distribution and saturable absorbers. All approaches are introduced in theoretical considerations and corresponding measurement results are presented. Additionally, numerical simulations are performed to gain an increased understanding of some of the mode selection mechanisms. The considered concepts are evaluated in terms of decrease of the series resistance (for impedance matching/driving reasons) and device lifetime ( as derived from maximum current densities) . The results obtained are also compared to other approaches found in literature (e. g. metal apertures, photocurrent feedback, Fabry-Perot étalon, half-symmetric cavity) . Conventional devices with optimized thin oxide aperture location have shown single-mode output powers above 4 mW with an active diameter of 3.5 pm. A record high single-transverse mode output power of 5 mW at a series resistance of 98 is obtained for a 7 pm aperture device by increasing the cavity length monolithically by 4 ,am.

Effect of oxide aperture on the performance of 850 nm vertical-cavity surface-emitting lasers

“…Depending on the requirements, VCSELs are invented according to the desirable operating wavelength [7,8]. Sophisticated design of VCSELs includes surface emission with high spectral performance, which makes the 2D array integration simpler, reducing thereby the manufacturing cost of the device.…”

Growth characterization of In<inf>x</inf>Ga<inf>1-x</inf>As/Al<inf>x</inf>Ga<inf>1-x</inf>As multi-oxide layer vertical-cavity surface-emitting lasers structure

“…Moreover, mode suppression layers are formed as alternative part by oxidized low index layers in DBR above the current confinement layer. Th~output roll-off of laser diodes is typically attrIbuted to the self-heating in continuous-wave operation [4][5]. The total heat power is generated at the output power maximum.…”

Three-terminal dual-stage vertical-cavity surface-emitting laser

“…The successful research into conventional vertical-cavity surface-emitting lasers (VCSELs) at 850 nm wavelength has led to mass-production of these devices for commercial shortdistance high-speed and parallel optical data communication systems. Today, the research is mainly focused on the development of reliable 1.3 and 1.55 µm VCSELs but also on the realization and investigation of new design concepts to overcome the bottlenecks of standard VCSELs such as tunability [1], singlemode power [2], dynamic behavior [3] and roundtrip gain [4]. In this letter we present the experimental results on a fabricated three-terminal dual-stage p-n-p VCSEL at 980 nm wavelength.…”